水稻根系分泌物脱氧麦根酸对根际和根内细菌群落组成的影响  

Effects of deoxymugineic acid from rice root exudates on bacterial community composition in rhizosphere and root endosphere

作　　者：杨临泽 寿惠霞[1,2] YANG Linze;SHOU Huixia(Hainan Yazhou Bay Seed Laboratory,Hainan Institute of Zhejiang University,Sanya 572025,Hainan,China;Institute of Plant Biology,College of Life Sciences,Zhejiang University,Hangzhou 310058,Zhejiang,China)

机构地区：[1]浙江大学海南研究院,海南省崖州湾种子实验室,海南三亚572025 [2]浙江大学生命科学学院植物生物学研究所,浙江杭州310058

出　　处：《浙江大学学报（农业与生命科学版）》2023年第3期376-388,共13页Journal of Zhejiang University:Agriculture and Life Sciences

基　　金：浙江省重点研发计划项目(2021C02053)。

摘　　要：缺铁条件下禾本科植物根系会向土壤内分泌麦根酸类物质。为明确水稻根系分泌物脱氧麦根酸对根际和根内细菌群落的影响,本研究以野生型水稻日本晴及其无2′-脱氧麦根酸(2′-deoxymugineic acid, DMA)分泌能力的2个突变体水稻osbhlh156、iro2为实验材料,对根际和根内微生物取样后进行DNA提取、16S rRNA基因扩增子测序和数据分析。结果表明:土壤类型和栽培方式显著影响了水稻根际、根内细菌群落的组成,而根系分泌物DMA对细菌群落的影响相对较小;细菌物种数量和多样性从根际到根内逐渐降低,因此根内细菌是在与植物的相互作用下被逐步定殖到根中的;水稻根际有无DMA分泌物可用慢生根瘤菌属(Bradyrhizobium)、火山盘杆菌属(Dictyobacter)等9个微生物类群(生物标志物)进行区分;具有三磷酸腺苷结合盒(adenosine triphosphate-binding cassette, ABC)转运蛋白相关功能的细菌可能参与了植物铁转运过程并行使相关功能。本研究结果明确了DMA对水稻根际和根内细菌群落组成的影响,为全面解析微生物在水稻缺铁响应过程中的作用提供了数据支撑。Under the iron-deficiency condition,roots of graminaceous plants secrete mugineic acids into the soil.To determine the effects of rice root exudate 2´-deoxymugineic acid(DMA)on rhizosphere and root endosphere bacterial community,wild type rice named as Nipponbare and osbhlh156 and iro2 mutant rices that loss the ability to secrete DMA were used as experimental materials in this study.The rhizosphere and root endosphere microorganisms were sampled for DNA extraction and 16S rRNA gene amplicon sequencing and data analysis.The results showed that soil types and cultivation conditions had significant impacts on rhizosphere and root endosphere bacterial community composition.In contrast,the root exudate DMA had relatively less impact,but not negligible.The bacterial species and diversity decreased from rhizosphere to root endosphere,which confirmed that the root endosphere bacteria were gradually selected and colonized inside root by interacting with plants.Nine microbial taxa,including Bradyrhizobium and Dictyobacter,etc.,were selected as biomarkers,to distinguish whether there is DMA secretion in the rice rhizosphere.Through functional prediction,it was found that the bacterial taxa with adenosine triphosphate-binding cassette(ABC)transporter function may be involved in plant iron transport and related function.This study clarifies the effects of DMA on the composition of rhizosphere and root endosphere bacterial community of rice and provides data support for the comprehensive analysis of the role of microorganisms in response to iron deficiency in rice.

关 键 词：水稻 缺铁 脱氧麦根酸 根际 根内 细菌群落 

分 类 号：Q945.15[生物学—植物学] S511.22[农业科学—作物学]